Mystery substance from fretboard - now stuck on my hands

toss that "cleaning tool" & stop oiling your fretboard
oiling fretboards is to make them look pretty for a while, otherwise there is no purpose to it:

oil vs. water

 

Both oil and water are volatile compounds, in that they have a vapor pressure that will cause them to evaporate, however slowly, into room-temperature air of moderate humidity. While oil and water classically don't mix, nature abounds with "emulsifiers" that get them to coexist better, because virtually all plant and vertebrate lifeforms on Earth use long-chain alkanes for energy storage and water for a variety of uses, especially nutrient transport.

Case in point, oils rubbed into the fretboard will stay there longer than water, and will avoid undue softening or swelling of the kiln-dried, stabilized lumber like water will do. However, anything thin enough to actually soak in and not just form a surface layer is also aromatic enough to evaporate back out. That doesn't mean it's pointless to oil the fretboard, it just means you can't do it just once and expect the neck to be fine forever. It also means that a freshly-oiled fretboard won't look like that for long, and you don't want it to as the look comes from a thin surface layer of oil (which, if made of a sufficiently diverse range of alkanes, will "dry" to a waxy crust), so if you like that glossy, three-dimensional look of oiled lumber, a more permanent hard-shelled finish like a lacquer will be a better option, assuming of course you also like the feel.

To the OP, that gunk is the residue of your fretboard oil. Whatever brand it is, it is apparently a mix of a wide range of "weights" of oil and wax, with the lighter, thinner oils acting as a solvent for the heavier waxes. You are very likely oiling your fretboard too much and/or too often, and the heavier waxes can't soak in before the lighter stuff evaporates, leaving behind a surface film of heavy waxes that attracts dirt.

You will need to dissolve and rub off this film without leaving another film behind. That calls for a lightweight cleaning oil; a thin mineral oil should do the job. Rub it on, leave it for a minute, then a little elbow grease and a clean rag will remove the fingerboard grime. If it's really caked on there, Murphy's Oil Soap (speaking of emulsifiers) is safe in moderation for most musical instrument woods. That means don't soak the neck in a bucket of the stuff; dampen a rag in the solution, scrub, and let air dry.

 

I repeat, unnecessary.

 

it's possible that someone went nuts with some silicone oil -like treadmill belt lube or something, but it's a mystery for sure. have you tried a mechanics type of soap on your hands? like Go-Jo, Zep heavy duty, etc..?

is it a glossy finished maple board or rosewood? the reason i ask is because if it's a glossy maple board the finish might be degrading from whatever's been put on it.

 

you need a bit of an abrasive along with a soap component and a conditioner. don't know what country you're in but can you get 20 Mule Team Borax with Lanolin?

mechanics hand cleaners like go-jo, fast orange, zep, etc.. -95% of the time gets stuff off your hands. 20 Mule Team Borax just gets it done period. you may need multiple applications though. sometimes you need to get in there with a old toothbrush lathered up with the hand cleaner as well.

 

The excess oil has polymerized. Get some naptha (lighter fluid) and clean it off.

 

I don't know what is on your hands but everything sounds wrong to me except what @Killed_by_Death has posted.

Silicone is slippery, not sticky. Wax doesn't soak into the wood. Oil doesn't stay around unless it is drying oil.

Another possibility with wear it came from is your strings. Some strings are coated to make them last longer. Whatever cleaning tool you use for the strings might have gotten that on you.

Rather than putting chemicals on your hands without knowing what your treating, I would suggest waiting a day or two and letting your skin correct itself before you end up giving yourself a chemical burn.

 

Silicone lubricants do indeed get gummier and eventually sticky, regardless of claims to the contrary. They keep a lubricating layer quite well, and are safe for most plastics and rubbers other than silicone rubber, which is why I use silicone lube, but a miracle slip-n-slide it ain't.

The other two points are exactly my point from the earlier post; waxes suspended in a lighter solvent oil are intended to soak in - the lighter oil carries the wax into the grain, then evaporates leaving the wax behind - but if the wood's already saturated the wax stays behind as a grimy film. Oils, especially lighter solventy weights of oils, definitely do not stick around.

 

Naptha

 

This makes me think the fingerboard was heavily coated with boiled linseed oil. WD40 will get it off your hands.

WD40 could get it off the fingerboard too but it can stain the wood in the process. A better, more thorough method would be to first scrape the wood between the frets with a single-edge razor blade which will get 90% of it off the surface. Then use solvent on a rag and possibly a stiff nylon brush to get the last 10% out of the grain.

For solvents, progress in this order until you find what works: naphtha (lighter fluid), mineral spirits, acetone, lacquer thinner.

Important Note: Be careful using solvents. Use small amounts, always on a rag, never poured directly on the wood. Keep solvents like acetone and lacquer thinner away from the finish. Naphtha is safe but anything more aggressive can do terrible things to a guitar finish.

 

I was thinking that or a heavy concentration of tung oil other than gunstock oil (Birchwood Casey Tru-Oil).

For scraping a fingerboard, fabricate a "J" blade from a common utility razor blade.

Riis

 

Naphtha as suggested.

Naphtha is the main ingredient in "silicone remover" that paint shops use to avoid "fish eyes" in the new paint.

It also of course removes waxes.

It won't soften or cloud your finish, and leaves nothing behind once it evaporates.

While you have the strings off, make sure you COMPLETELY clean them with Naphtha, because they are now very contaminated.

If your fretboard is very porous, with lots of graining, you might even use a soft toothbrush with the Naphtha

It will leave your fretboard very dry looking; lightly oil and you will be good for a year or two.

Naphtha even cleaned this 80s BC Rich that a customer brought in:

 

Some people are saying oil won't stick around. It definitely will. the oils used on fretboards are not volatile. They will soak in to the wood to some degree but after that they will form the gummy mess described. This is why if you oil a board use a tiny amount, wipe off access aggressively, and do it very infrequently.

 

When i asked the best guitar tech i’ve ever known about oiling rosewood, he said if you have to do it, use a tiny amount of plain vegetable oil and a lot of elbow grease. In my entire life I’ve had one rosewood board I felt needed some oil. It looked like the previous owner had use some type of preparation on it that dried the wood and left a silvery white powdery residue in the pores of the wood. I scrubbed it with a worn out toothbrush slightly dampened with warm water, then wiped it down real good. I then spent a couple hours rubbing about a tablespoon of cooking oil back into it.
as for cleaning your hands, denatured alcohol with a bit of liquid dish soap cut in has always worked to get fresh (uncured) epoxy off my hands, but i wouldn’t try it on a fretboard as it would dry it out big time.